The invention relates to a rail system and a gas metering system utilized in a hyperbaric transfer system. Such a hyperbaric transfer system has been developed by Mr. Andre Galerne and is the subject of a related copending application, Ser. No. 892,867 filed concurrently herewith. The disclosure of the Galerne application is hereby incorporated by reference.
Offshore diving operations have brought tremendous problems to divers who are called upon to perform heavy construction work at depths and in diving conditions that border on the limits of underwater technology. The risk of serious trauma exists and with the use of saturation techniques there is a danger of acute illness while the diver is under pressure.
Divers who work at great depths for considerable amounts of time must undergo decompression for periods up to two weeks. Normally, the decomposition takes place in a conventional decompression chamber on the offshore rig. However, in rig abandonment situations or in situations in which a diver is seriously injured, it may be necessary or desireable to leave the offshore decompression chamber.
The system described in the copending Galerne application is a system for transferring the divers undergoing decompression from the offshore rig to another hyperbaric facility.
However, since the vessels of the hyperbaric transfer system are relatively small in comparison to conventional decompression chambers and hyperbaric facilities, the hatch openings also are relatively small. A diver being transferred is often incapacitated and must be assisted when being moved in and out of the transfer vessels. Due to the small opening size, which can be 25 to 30 inches at its widest point, as well as the limited space within the hyperbaric transfer vessels, the transfer of an injured diver between chambers can be difficult and dangerous. Transferring the injured diver through such a small opening can cause unnecessary disruption of the patient. For instance, if the patient has a broken limb, the limb should be completely immobilized. Transfer of the patient between chambers could easily disrupt the limb and cause additional injury. Even if the injured diver can be transferred into and out of the transfer vessel without disrupting his condition, the transfer is slow and ordinarily requires more than one person to effect the transfer safely. In some situations, there only may be one person available to aid in the transfer.
Once the divers are inside the vessels of the transfer system, their condition must be kept stable. In keeping with this objective, the problem arises of keeping the gas mixtures constant within the vessels of the transfer system. This includes both the pressures and concentrations of the compression gas, the breathing gas and the oxygen within the chamber. It is especially true for the oxygen supply within the vessel which must be replenished as it is used. Until now, the oxygen could be regulated by feeding oxygen into the vessel and providing the vessel with an oxygen analyzer which would measure the gas concentration within the vessel. Similar analyzers and meters could be provided for compression or breathing gas mixtures. However, the process of feeding gas into the chamber, waiting for the pressure or concentration within the vessel to stabilize and reading the analyzer is slow and requires the complete attention of the individual performing the operation. In an emergency situation, such as a fire on the offshore rig, the time necessary to take an accurate measurement is not available. The persons moving the vessel have all they can do just moving the vessel or removing the vessel from the offshore rig. Furthermore, in an emergency situation, there is no assurance that personnel capable of accurately metering gas into the vessel and reading the analyzer will be available.